Many of electronic devices having information processing functions, typified by a personal computer and the like, include electronic components, such as a CPU, which produce heat while executing processes. The electronic component itself such as the CPU is a heat-producing element and may cause malfunction when a temperature thereof is excessively increased. Thus, most of the electronic devices such as the personal computer are internally equipped with some kind of means for cooling the electronic component such as the CPU.
Although different from the cooling of electronic components inside an electronic device, an air conditioner or the like for keeping a room temperature constant in a building employs, for example, a method of using a cooler that is installed in the middle of a circulation path for sucking air from the inside of the room to send the sucked air to the outside thereof and for returning the air into the room again by using a fan (see, for example, Japanese Laid-open Patent Publication No. 06-94255). Moreover, as an example of the cooling of electronic components in an electronic device having an airtight structure, there has been proposed a technique including: generating an air flow around electronic components by using a fan installed in the electronic device; causing the air flow to absorb heat of the electronic components; and radiating heat of the electronic components to the outside of the electronic device through a heat exchanger while maintaining the airtightness inside the electronic device. Here, the heat exchanger is provided to transfer the heat of the air in the electronic device to the air outside the electronic device (see, for example, Japanese Laid-open Patent Publication No. 2003-23284).
As an example of the cooling of electronic components such as the CPU, an electronic device such as a personal computer that does not particularly require airtightness or the like often employs a simple method compared with the above examples. Specifically, in the simple method, heat of the electronic components is collected into a heat radiating section including heat radiating fins and the like. Thereafter, air is blown onto the heat radiating section by a fan and then the air that has absorbed the heat in the heat radiating section is discharged directly to the outside of the device.
Here, in the simple cooling method for the electronic components in the electronic device such as the personal computer, like the one described above, foreign substances such as dust may be present in the air blown by the fan. Thus, in order to prevent such foreign substances from clogging the fins of the heat radiating section or the like, a filter for removing the foreign substances may be installed between the heat radiating section and the fan. The installation of the filter is more likely to cause phenomena, in turn, such as one in which the air hitting against the filter partly veers off the direction heading toward the heat radiating section. Accordingly, cooling efficiency is lowered, which may cause insufficient cooling of the CPU and the like that produce heat more than ever due to a recent increase in processing speed, and the like.